The brightness looks great everywhere else on my computer (it's not a laptop, but a real tower with a 27" monitor). If I change the brightness of my monitor, it looks better in the game, But then everything else looks way too bright. I can't see borders and certain text on websites since it's all too bright. So it's something with the game.
Also, as I mentioned, the Gamma slider simply doesn't work. When I move it to the left, the brightness does nothing and goes down to 30% without changing the brightness. If I go to the right, it does nothing but the value in the slider turns green at 100%. If I continue going to the right, the value turns red and the display gets darker and darker until it maxes out at 300% and is very dark. The brightest is if I keep it at just under 100% it seems.